References for Galatians 3:13

14
Christ did this in order that the blessing which God promised to Abraham might be given to the Gentiles by means of Christ Jesus, so that through faith we might receive the Spirit promised by God.

15
My friends, I am going to use an everyday example: when two people agree on a matter and sign an agreement, no one can break it or add anything to it.

16
Now, God made his promises to Abraham and to his descendant. The scripture does not use the plural "descendants," meaning many people, but the singular "descendant," meaning one person only, namely, Christ.

17
What I mean is that God made a covenant with Abraham and promised to keep it. The Law, which was given four hundred and thirty years later, cannot break that covenant and cancel God's promise. 2

References for Galatians 3:18

19
What, then, was the purpose of the Law? It was added in order to show what wrongdoing is, and it was meant to last until the coming of Abraham's descendant, to whom the promise was made. The Law was handed down by angels, with a man acting as a go-between.

20
But a go-between is not needed when only one person is involved; and God is one. a